1. Field of the Invention
The present invention relates to a method and a device using ultrasound for inspecting the surface state of a bore, especially the bore of a railroad wheel axle.
2. Discussion of the Background
Railroad wheel axles are long parts of revolution, in which an axial bore is machined, over their entire length, by drilling. The surface of the bore is inspected so as to check that it doesn't include any defects, such as a tool blow, running the risk of decreasing the fatigue strength of the wheel axle. For this purpose, it has been proposed to carry out roughness measurements. However, these measurements can only be carried out in the vicinity of the ends of the wheel axle. It is also known to carry out an inspection using ultrasonics from outside the wheel axle. However, this method does not enable the complete bore to be inspected. In fact, the wheel axle includes several cylindrical portions connected by connection fillets. In the zones located in the vicinity of these connection fillets, it is not possible to carry out an inspection using ultrasonics from outside. Furthermore, this method is lengthy as it is necessary to scan the entire surface of the axle.